[rules-users] Benefits of pluggable operators

What are the benefits of using pluggable operators (implementations of org.drools.base.evaluators.EvaluatorDefinition such str, matches, or before) versus simply making an equivalent function call? I've read the Creating pluggable operators<http://blog.athico.com/2010/06/creating-pluggable-oprators.h... blog post. Apart from saying that the Eclipse plugin can recognize these operators, it doesn't really make a case for why I'd want to create my own implementation. One might argue that operators enhance reusability, but a static method offers much the same benefit. Does a pluggable operator have any optimization, caching, or other advantage? For example, here are two ways to match the start of a string in a property of a fact, one using the "str[startsWith]" operator and another with Java's String.startsWith method: declare Fact key : String @key end rule "Use operator" when Fact(key str[startsWith] "abc") then // do something end rule "Use method" when Fact(key.startsWith("abc")) then // do something end Does one of these perform better than the other? Best wishes, Tom